Terbium is the ninth member of the Lanthanide series, being located in the first row below the periodic table of elements. It is a silvery-white metal with a melting point of 1356 degrees Celsius. It was identified in 1843 by Johan Gadolin. It is one of multiple elements discovered near Ytterby, Sweden. 

Terbium can be used in light bulbs, Lasers, and X-ray machines. When alloyed with Iron and Dysprosium, it can be used to create loudspeakers which can adhere to a flat surface and turn it into an amplifier.